A company called Blue Sky Positioning has announced that it has managed to fit a complete GPS solution onto a SIM card. In so doing, they had to solve a number of technical challenges such as the limitation to draw no more than six milliamps of power, working out how the embedded antenna would work given that it would be enclosed by the phone and a fair amount of metal, and how to process all of the necessary data.
Depending on which device the SIM is in, the user could get no more than SMS responses to location queries (for example, where is the nearest restaurant?) right up to a complete service that would include mapping, location, and route-planning capabilities on more powerful devices.
Blue Sky Positioning already has prototypes and expects to start production in July.